Set-screw.



' L. J. VMoLLoY.

SET SCREW.

APPLIUATION FILED BEPT.14,1908. Y 907, 1 60, Patented Dec. 22, 1908.

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UNITED STATES JEO J. MOLLO'Y, OF BUFFALO,l NEW YORK.

SET-SCREW.

Application filed September T o allwho'm it may concern: y

Beit known that I, LEO J. MoLLoY, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York,

have invented certain new and useful Improvements in Set-Screws, of which the following is a speciication.

'Ihis invention relates to an improved setscrew, and it has for its object the production of a screw particularly adapted for securing conduit-pipes in condulets but it may also be used generally where set-screws are employed and impinge with their ends against a hard surface.

It also has for its object the production of a set-screw which will bore into a hard surface and will expand radially in the region of the end thread or threads, so `as to impinge forcibly against the cooperating threads of the 2O tapped opening into which the` screw is threaded.

A still further object is, the production of a set-screw comprising two members so related, that one serves to expand the end of the other and prevent loosening of the screw by jarring of the parts. i

with these and other objects in view, the invention consists of an externallythreaded outer member and an internal impingingso member held by said outer member against the object fastened.

It also consists in the construction, arrangement, and combination of the parts constituting said set'screw as hereinafter described and particularly pointed out in the subjoined claims.

In the drawings,-Figure l is a sectional elevation of an electric wire-conduit showing the conduit-pipe fastened into a condulet by 40 means oi my improved set-screw. Fig. 2 is a horizontal section taken on line 2--2, Fig. l. Fig. 3 is an enlarged sectional elevation of my improved setscrew. Figfll is an enlarged longitudinal section of the outer member ci the same. Fig. 5 is an enlarged elevation of the inner impinging member.

Referring now to the drawings in detail, like letters of reference refer to like parts in the several iigures. y

Experience has shown that set-screws ot the common type when used to impinge against a hard surface, will not, in many eases, withstand the slight jar to which they are subjected, without becoming loosened and the parts intended to be secured thereby becoming unfastened, and'for this reason, it

Specification of Letters Patent.

Patented Dec. 22, 1908.

14, 1908. Serial No. 452,988.

has been the practice in connecting conduitpipes to condulets to externally thread the ends of said pipes and screw the same into the internally threaded ends of the condulets. rI his is not only expensive, but inconbetween the condulets being unequal so that the conduit-pipes must be cut to the lengths required and then threaded for connection with the condulets. Furthermore, the conduit pipes are enameled and by gripping the same with a pipe-wrench in order to fasten them within the threaded ends of the conduotherwise marred. While I have particularly designed this set-screw for the connection of conduit-pipes to condulets, it may be used Jfor fastening pulleys upon shafts and wherever set-screws are employed; particularly, where such screws are subjected to jar and there is a tendency of the same becoming loosened.

To show the application of this improved set-screw, I have illustrated a conduit for electric wires in which A represents the condulet having a lateral extension B, and into the said extension and the ends of said con dulet which are smooth bored, I insert conduit-pipes C, the inserted ends of which are unthreaded.

D are the circuit-wires passing through the conduit and joined within the oondulet. The ends of the conduit pipes are fastened in the condulet by means oi' my improved setscrew. This set-screw comprises an outermember E having a central longitudinal bore e extending from end to end thereof and beveled or countersunk at the inner end of said bore, as shown at el. Said outer member also has the usual square head dat its outer end and it is externally threaded, at at e3, similar to the ordinary set-screw; said outer member is threaded into a tapped opening a formed in the condulet. Fitting in said longitudinal bore e is an impinging member F somewhat longer than the outer member so as to project Jfrom opposite ends thereof. The inner end of said impinging-member has an enlarged oppositely tapered head f to provide a flaring expander-portion f1 which cooperates with the countersunk end e1 of the bore e and a pointed or conical impinging portion f2 which is adapted to be forced into the metal oi the conduit pipe, in the manner shown in Fig. 2.

In using the set-screw to fasten an object,

lets, the enamel will become chipped and venient as well, on account of the distances lmember the impingingl member is thrust into the externally-threaded outer member so that it projects from both ends oi' the latter, as shown in Fig. 3. arranged, the set-screw is threaded into the tapped opening land by reason of the expander-portion f1 being seated against the countersunk portion of the bore e, the impinging-member is forced against the object to be fastened. 5 but in order that assurance `is had of a secure fastening, the outer projectingend of said member `is to be struck with a hammer or other object so as vto drive the pointed or conical inner yend thereof into the metal of the object fastened. By striking the impinging-member, the expander-portion f1 thereof is forced away from the countersunk end of the bore e formed in said outer member, thus permitting the latter to be screwed farther into the tapped opening. .Vhen the pointed or conical end of the impinging-member is driven into the metal `of the object fastened to the extent desired, the outer member is screwed tight against the expander portion 1 whereby the inner end of said outer member is expanded so that the threads in the region of the counter-sunk parit e1 are forcibly crowded into the coperating threads of the tapped opening g thus securing a positive'fastening and at the same time preventing accidental unscrewing of the outer-member.

Having thus described my invention, what I claim is,-

l.. A set-screw comprising a hollow threaded outer member and an lmpinging-member fitting into said outer member and having an enlarged portion against which the-inner end of said outer member bears, said limpingingbeing adapted to impinge against the object to be fastened.

With the two parts thus 2. A set-screw comprising an externally# threaded outer member having a head at its outer end and provided with a longitudinal bore, and an impinging-member fitting into said bore and having an enlarged and pointed end portion against which the inner end of said outer member bears.

3. A set-screw comprising an outer externally-threaded member provided with a longitudinal bore, and an impinging-member iitting into said bore and extending from opposite ends of said outer member, said impinging-member having a pointed enlargement at its inner end against which the inner end of said outer member bears.

4. A set-screw comprising an externallythreaded outer member provided with a central longitudinal bore beveled at one end to form a countersunk portion and an impinging-member fitting into said bore and extending from opposite ends of said outer member, said impinging-member having an oppositely-tapered enlargement providing an expander-portion fitting into the countersunk portion of said bore and a conical im.- pinging portion adapted to be driven into the metal of the object fastened. L

5. A set-screw comprising an externallythreaded member provided with a central longitudinal bore, and an impinging-member fitting into said bore and provided with means for expanding the inner end of said outer member.

In testimony whereof, I have affixed my signature in the presence of two subscribing witnesses.

LE() J. MOLLOY.

Witnesses:

ELLA C. PLUECKHAHN, EMIL INEUHART. 

